bdking writes: More than 140 sponsors have pulled their ads from Rush Limbaugh's syndicated radio show since the right-wing talk host called a Georgetown University law student a "slut" two weeks ago. Limbaugh is no stranger to controversy, but "Slutgate" is the first big one since social media began helping to shape public debate and corporate strategy. If social media continues to fuel an advertiser exodus, will this be the beginning of the end for Limbaugh and his national platform?